A circuit module may be connected to a circuit board so that it may communicate with other circuit modules through the circuit board. The connection of a circuit module to a circuit board has two aspects. First, there must be a good mechanical connection of the circuit module to the circuit board to ensure that the circuit module is securely fastened to the circuit board. Second, there must be an electrical connection between the circuit module and the circuit board to ensure that the circuit module can communicate with other circuit modules through the circuit board.
One method of connecting a circuit module to a circuit board is by a through-hole connection. For a through-hole connection, the signal lines of a circuit module are coupled to pins that emanate from the circuit module package. These pins are then inserted into plated through-holes in the circuit board. The plated through-holes are then filled with solder to mechanically connect the circuit module to the circuit board and to electrically connect the signal on the circuit module through the pin to the plated through-hole.
Another method of connecting a circuit module to a circuit board is by surface mount technology. One surface mount method uses leads shaped like the wings of a seagull. The gull-wing leads emanate from the perimeter of the circuit module package. The circuit module is oriented so that its gull-wing leads rest on conductive pads on the circuit board which are coated with a solder paste. The solder paste is then re-flowed to mechanically and electrically couple the gull-wing leads to the circuit board.
A ball grid array is another form of surface mount technology that eliminates the need for pins and the gull-wing leads. For a ball grid array, an array of conductive pads are formed on the bottom of a circuit module. A corresponding array of conductive pads are formed on the circuit board. To attach the circuit module to the circuit board, balls of solder are formed on the conductive pads of the circuit module. The circuit module is then placed on the circuit board with their corresponding conductive pads aligned. The circuit module and the circuit board are then sent through a re-flow furnace to form a metallurgical solder joint to mechanically and electrically couple the conductive pads of the circuit module to those of the circuit board.
After the circuit module has been attached to the circuit board, regardless of the method of attachment, the functionality of both the circuit board and the circuit module are often tested. If the circuit module is not functioning properly, it is replaced with another circuit module. If the circuit module was attached to the circuit board using one of the methods described above, the solder must be heated to allow removal of the circuit module from the circuit board. The circuit board is then prepared for the installation of the new circuit module.
For example, when an improperly functioning circuit module is mounted to a circuit board using ball grid array technology, the assembly of the board and module must be heated to melt the solder. The improperly functioning circuit module may then be removed from the circuit board. The conductive pads on the circuit board are prepared for a new module by removing any of the solder remaining from the solder used to attach the improperly functioning circuit module. The new circuit module may then be attached to the circuit board.
The method used to attach a circuit module to a circuit board often presents a compromise between the strength of attachment and the number of signal lines being coupled between the circuit board and the circuit module for a given board area. For example, through-hole connections provide secure attachment of the circuit module to the circuit board, but the pins are large and result in a reduced number of signal lines being coupled from the circuit module to the circuit board for a given board area. A similar compromise is encountered when attaching a circuit module to a circuit board using a ball grid array. For a given circuit board area, if the conductive pads are too small, the attachment will be weak. In contrast, if the conductive pads are too large, there is a risk of a solder bridge shorting adjacent conductive pads.
To overcome the shortcomings of conventional methods of attachment, a new removably interlockable assembly is provided. An object of the present invention is to provide an assembly having a connector that may be removably interlocked with a compatible connector. Another object is to provide a conductive removably interlockable assembly. A further object is to provide a connector for attaching circuit modules to circuit boards. Yet another object is to provide a removably interlockable solderless connection of a circuit module to a circuit board.